Sliding Sleeve Valve and Shifting Tool Therefor

ABSTRACT

A sliding sleeve valve comprises a sliding sleeve having an internal profile along the length thereof, wherein the internal profile has a length that is less than the length of the sleeve and wherein the profile is adapted to engage a sleeve shifting tool. A sleeve shifting tool comprises sleeve engagement arms, for engaging a sliding sleeve of a sliding sleeve valve, wherein the sleeve engagement arms are hydraulically driven by a reciprocally rotating mandrel. An indexing tool allows rotation of the shifting tool to be achieved by axially moving a work string.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority under the Paris Convention to U.S. Application No. 62/885,964, filed on Aug. 13, 2019. The content of such prior application is incorporated herein by reference as if set forth in its entirety.

FIELD OF THE DESCRIPTION

The following description generally relates to devices for controlling fluid flow into and out of tubing strings used in hydrocarbon wells. More particularly, the present description relates to sliding sleeve valves used in tubing strings. The description also relates to shifting tools for selectively opening and closing such sleeve valves.

BACKGROUND

In the field of hydrocarbon production, a wellbore is drilled into a hydrocarbon-containing subterranean formation, and a tubing string, or production tubing, is then provided within the wellbore for providing fluid communication from the formation to the surface. The tubing string may in some cases be cemented within the wellbore. Tubing strings comprise a plurality of generally axially (i.e. end to end) connected tubular elements, along with any number of tools, or “tool subs”, also provided coaxially as part of the tubing string. Such tools include valve subs (discussed further below), packers, and others. Many other tools would be known in the art.

Typically, a tubing string used for hydrocarbon wells is provided with a plurality of ports or openings at desired locations or sections along its length, which are adapted to allow fluids to flow into or out of the tubing string. For example, in the case of a fracking operation, a high-pressure fluid is injected into the subterranean formation through ports in the tubing (and through the cement lining if present) to create fractures in the formation. Once the pressure applied to the formation is reduced, these fractures allow hydrocarbon materials in the formation to be released. Thereafter, the released hydrocarbons are “produced” by allowing the materials to flow into the tubing string through the ports, and ultimately brought to the surface. The equipment used for such production operations would be known to persons skilled in the art.

In view of the length of such strings and/or in view of permeation and other differences in subterranean formations into which the wells are drilled, it is often necessary to provide some means of controlling the flow out of or into the tubing string. For this purpose, it is common to have valves on the ports provided on tubing strings so that fluid flow is restricted to one or more desired locations there-along. For example, in the case of fracking, it is desirable to only create fractures at discrete locations in the formation along the length of the tubing string. Similarly, in the case of production, it is desirable to close or shut off one or more ports along the tubing string where fluids such as water, gas, etc., are preferentially produced over oil. For this purpose, it is common to utilize valves comprising sliding sleeves that are coaxially incorporated in the tubing string and which serve to cover, or close the ports provided on the string. Such “sliding sleeve valves” comprise a generally tubular sub having a sleeve slidably provided within a housing, with the housing being adapted to form part of the tubing string. The sliding sleeves are adapted to be axially moveable, in relation to the housing, between a “closed port” position, where the sleeve covers the ports, and an “open port” position, where the sleeve is moved away from the port, thereby allowing the port to form a channel through the tubing string. Consequently, the port (or ports), once opened, create a channel to allow fluid communication between the interior of the tubing string and the reservoir across the tubing string wall. In many cases, the sliding sleeve valve comprises a separate tubular sub or tool that is connected, end to end, to adjacent tubular members, thereby forming a part of the tubing string. Although the ports mentioned herein are indicated as being provided on the tubing string, it will be understood the ports are typically provided on the sub comprising the sliding sleeve valve.

Various methods are known for moving the sliding sleeves of sliding sleeve valves to open/or close the port(s) provided thereon. In one example, the sleeve may be provided with a region of reduced internal diameter to form “seat” for sealingly engaging a ball that is dropped into the tubing string from the surface. Once the ball is seated, fluid pressure within the tubing string upstream of the ball is increased, thereby causing the sleeve, initially in the closed port position, to slide in the downstream direction and thereby open the port(s). Another means of moving the sliding sleeves involves the use of a sleeve shifting tool. Such shifting tools are typically provided on a work string, such as coiled tubing, and are run downhole through the tubing string. When the shifting tool reaches a location near a selected sliding sleeve, the tool may be actuated and manipulated to engage the sliding sleeve. The shifting tool is then moved axially within and with respect to the tubing string, thereby causing the sliding sleeve to be axially moved with respect to the tubing string. The sleeve is moved to expose (open) or cover (close) the ports associated with the sleeve. While some shifting tools are designed for only unidirectional movement of the sliding sleeve, i.e. to either open or close ports, other tools are capable of sliding the sleeve in either direction, to either open and/or close the ports.

One example of a known bidirectional shifting tool is described in U.S. Pat. No. 9,638,003, which discloses a valve sub comprising a sliding sleeve as discussed above. The sleeve is provided within a cylindrical body, which is adapted to be connected to adjacent tubular members of a tubing string. The sliding sleeve has a constant inner diameter and opposing ends and is retained within the cylindrical body by means of retaining, or snap rings, which engage corresponding grooves provided on the inner surface of the cylindrical body. US '003 also discloses a shifting tool having hydraulically actuated sleeve engaging members for engaging the opposite ends of the sleeve and to move same with respect to the tubular body. In operation, the shifting tool is run downhole to the location of the sliding sleeve and actuated to engage and thereafter move the sliding sleeve. Axial movement of the sleeve is limited by annular shoulders provided in the cylindrical body. The shoulders also act on the shifting tool to disengage the sleeve once the shifting tool encounters the shoulders.

A further sliding sleeve actuator is described in US 2017/0058644.

With many of these known actuation or shifting tools, accurate engagement with the sleeve is often difficult to achieve. Similarly, with many of the known shifting tools, another problem that is faced relates to premature disengagement of the sleeve prior to achieving a fully open or fully closed position. In either case, the efficiency of the fracking or production operation is reduced and, in some cases, jeopardized. As a result, the entire tubing string may need to be extracted and a new tool run in, resulting in lost productivity and increased costs.

A need exists for an improved sliding sleeve valve and/or an improved shifting tool for sliding sleeves.

SUMMARY OF THE DESCRIPTION

In one aspect, the present description provides a sliding sleeve valve having a sliding sleeve with a profile portion of a lesser length than the sleeve and which is adapted to engage a shifting tool.

In another aspect, the present description provides a hydraulically actuated shifting tool for engaging and moving a sliding sleeve of a sliding sleeve valve, wherein the shifting tool comprises sleeve engaging arms that are reversibly extendable and a mandrel for driving the sleeve engaging arms.

In one aspect, there is provided a sliding sleeve valve for a tubing string, the valve comprising a generally tubular structure having a longitudinal axis and a first connecting end and a second connecting end, the first and second connecting ends being connectable to tubing string components, the valve comprising:

a first sub, having a first end comprising the first connecting end and a second end;

a second sub, having a first end comprising the second connecting end and a second end;

a generally cylindrical housing extending between the first and second subs and having first and second ends, and a wall having an interior surface; and,

a generally cylindrical sliding sleeve coaxially located within the housing and having first end facing the first sub second end and a second end facing the second sub second end;

wherein:

-   -   the housing first end is connected to the first sub second end,         and the housing second end is connected to the second sub second         end;     -   the housing wall includes at least one port for providing fluid         communication through the wall; and,     -   the interior surface of the wall has a profile defining at least         first and second circumferential grooves provided at spaced         separate locations along the longitudinal axis;     -   the sliding sleeve is slidable, with respect to the housing,         along the longitudinal axis of the valve;     -   sliding of the sliding sleeve within the housing is limited by         the first sub second end and the second sub second end;     -   the sleeve is slidable between a closed port position, where the         sleeve covers the at least one port, and an open port position,         where the sleeve does not cover the at least one port;     -   the sleeve has an inner surface with a region with reduced         internal diameter, wherein the length of the region of reduced         internal diameter is less than the length of the sleeve and         wherein the region of reduced internal diameter defines a         cross-sectional profile, the profile having opposed shoulders;         and,     -   the sleeve includes a locating means adapted to engage the first         groove or second groove, wherein the locating means is engaged         within the first groove when the sleeve is in the closed port         position and wherein the locating means is engaged within the         second groove when the sleeve is in the open port position.

In another aspect, there is provided a shifting tool for shifting a sleeve of a sliding sleeve valve, the shifting tool comprising a generally cylindrical body having a lumen and a longitudinal axis, the shifting tool comprising:

two or more sleeve engagement arms provided on the cylindrical body, wherein:

-   -   the sleeve engagement arms comprise elongate elements having         longitudinal axes generally parallel to the longitudinal axis of         the cylindrical body;     -   each of the sleeve engagement arms having opposed ends pivotably         connected to the cylindrical body, whereby the arms are radially         extendable away from the cylindrical body and reciprocate         between a retracted position and an extended position;     -   each of sleeve engagement arms having a pair of spaced apart         sleeve engagement fingers provided on opposite ends thereof,         each pair of sleeve engagement fingers defining a sliding sleeve         engagement space there-between;

an elongate mandrel having a longitudinal axis and extending generally coaxially through the cylindrical body, wherein:

-   -   the mandrel is rotatable about its axis within the cylindrical         body;     -   the mandrel includes a first portion connected to a rotation         means; and     -   the mandrel is provided with pivot linkages for pivotably         connecting with each of the sleeve engagement arms;     -   a force transferring means, for transferring rotational motion         of the mandrel to extend the at least two arms between the         retracted and extended positions.

In another aspect, there is provided an indexing tool for rotating a tool provided on a work string. The indexing tool being actuated with an axial force and causing rotation of the other tool along its longitudinal axis.

In another aspect, a means of actuating a sliding sleeve valve is provided, wherein the sliding of the sleeve is controlled and monitored.

BRIEF DESCRIPTION OF THE FIGURES

The features of certain embodiments will become more apparent in the following detailed description in which reference is made to the appended figures wherein:

FIG. 1a is a side view of a sliding sleeve valve according to one aspect of the description.

FIG. 1b is a top, side perspective view of the sliding sleeve valve of FIG. 1 a.

FIG. 1c is a bottom, side perspective view of the sliding sleeve valve of FIG. 1 a.

FIG. 2 is a side cross-sectional view of the sliding sleeve valve of FIG. 1 a.

FIG. 3 is another side cross-sectional view of the sliding sleeve valve of FIG. 1a , showing the sliding sleeve in a first, or fully closed port position.

FIG. 4 is a side cross-sectional view of the sliding sleeve valve of FIG. 1a , showing the sliding sleeve in a second closed port position.

FIG. 5 is a side cross-sectional view of the sliding sleeve valve of FIG. 1a , showing the sliding sleeve in a first open port position.

FIG. 6 is a side cross-sectional view of the sliding sleeve valve of FIG. 1a , showing the sliding sleeve in a second, of fully open port position.

FIG. 7 is a side view of a shifting tool according to an aspect of the description.

FIG. 8 is a top view of the shifting tool of FIG. 7.

FIG. 9 is a side cross-sectional view of the entire shifting tool of FIG. 7, taken along line A-A shown in FIG. 8.

FIG. 10 is a side cross-sectional view of the shifting tool of FIG. 7 according to another aspect.

FIG. 11 is an enlarged end cross-sectional view of the shifting tool of FIG. 10, taken along the line A-A shown in FIG. 10.

FIG. 12 is an enlarged end cross-sectional view of the shifting tool of FIG. 10, taken along the line B-B shown in FIG. 10.

FIG. 13 is a partial side cross-sectional view of the shifting tool of FIG. 10 in a retracted position, showing a side view of the sleeve engagement sub and a cross-section view of the driver sub.

FIG. 14 is a bottom end view of the shifting tool shown in FIG. 13.

FIG. 15 is a partial side cross-sectional view of the shifting tool of FIG. 10 in an extended position showing a side view of the sleeve engagement sub and a cross-section view of the driver sub.

FIG. 16 is a bottom end view of the shifting tool shown in FIG. 15.

FIG. 17 is a partial side cross-sectional view of the shifting tool of FIG. 10 in a back-driven position showing a side view of the sleeve engagement sub and a cross-section view of the driver sub.

FIG. 18 is a bottom end view of the shifting tool shown in FIG. 17.

FIG. 19 is a top, side perspective view of the shifting tool shown in FIG. 13.

FIG. 20 is a top, side perspective view of the shifting tool shown in FIG. 15.

FIG. 21 is a top, side perspective view of the shifting tool shown in FIG. 17.

FIG. 22 is a side cross-sectional view of the shifting tool of FIG. 13 in combination with a sliding sleeve valve of FIG. 2.

FIG. 23 is a side cross-sectional view of the shifting tool of FIG. 15 in combination with a sliding sleeve valve of FIG. 2, wherein the shifting tool has engaged the sliding sleeve while the sleeve is in the port closed position.

FIG. 24 is a side cross-sectional view of the shifting tool of FIG. 15 in combination with a sliding sleeve valve of FIG. 2, wherein the shifting tool has axially moved the sliding sleeve to the port open position.

FIG. 25 is a side cross-sectional view of the shifting tool of FIG. 17 in combination with a sliding sleeve valve of FIG. 2, wherein the shifting tool has disengaged the sliding sleeve and in a back driven.

FIG. 26 is top, side perspective view of the shifting tool and sliding sleeve valve as shown in FIG. 22.

FIG. 27 is top, side perspective view of the shifting tool and sliding sleeve valve as shown in FIG. 23.

FIG. 28 is top, side perspective view of the shifting tool and sliding sleeve valve as shown in FIG. 24.

FIG. 29 is top, side perspective view of the shifting tool and sliding sleeve valve as shown in FIG. 25.

FIG. 30 is a perspective view of the shifting tool in the retracted position.

FIG. 31 is a perspective view of the shifting tool in the extended position.

FIG. 32 is an enlarged side cross-sectional view of the driver sub of the shifting tool.

FIG. 33 is a perspective view of the driver sub shown in FIG. 32.

FIG. 34 is an enlarged side cross-sectional view of another aspect of a nozzle provided on the first piston.

FIG. 35 is a perspective, partial cross-sectional view of the nozzle of FIG. 34.

FIG. 36 is a side perspective view of the second rotating mandrel of the shifting tool according one aspect.

FIG. 37 is a side cross-sectional view of the mandrel of FIG. 36.

FIG. 38 is a side perspective view of a shifting tool combined with an indexing tool.

FIG. 39 is an enlarged view of a portion of FIG. 38.

FIGS. 40 and 41 are perspective cross-sectional views of the indexing tool of FIG. 38.

FIG. 42 is a side perspective view of the “J” barrel of the indexing tool of FIG. 38.

FIG. 43 is a side perspective view of the lug ring of the indexing tool of FIG. 38.

DETAILED DESCRIPTION

As used herein, the term “sub” will be understood to mean a tubing string component, such as a tubular member, a coupling, a tool etc. as known in the art. As also known, a sub has a generally cylindrical structure and is adapted to be connected to adjacent tubular members, or other subs, to form the tubing string. As with typical tubular members, a sub may have a female or “box” end and a male or “pin” end. The box end includes an internal threaded portion that is adapted to receive and threadingly engage an external thread provided on a pin end of an adjacent component (e.g. a tubular member, a sub, or a tool etc.). In this way, all components of the tubular string are connected together in an end to end manner.

The term “tool” as used herein will be understood to refer commonly known tubing string components that are used for performing various tasks. Examples of tools include valves, such as sliding sleeve valves, packers, and the like.

The term “port” will be understood to mean an opening, aperture, or the like, that is provided to allow the flow of fluid therethrough. As used herein, a port comprises an opening provided on the wall of a tubular body for forming a fluid channel into the lumen of the body.

The terms “comprise”, “comprises”, “comprised” or “comprising” may be used in the present description. As used herein (including the specification and/or the claims), these terms are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not as precluding the presence of one or more other feature, integer, step, component or a group thereof as would be apparent to persons having ordinary skill in the relevant art. Thus, the term “comprising” as used in this specification means “consisting at least in part of”. When interpreting statements in this specification that include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in the same manner.

The term “and/or” if used herein can mean “and” or “or”.

Unless stated otherwise herein, the article “a” when used to identify any element is not intended to constitute a limitation of just one and will, instead, be understood to mean “at least one” or “one or more” unless indicated otherwise.

The terms “top”, “bottom”, “up”, or “down” may be used herein. It will be understood that these terms will be used purely for facilitating the description and, unless stated otherwise, are not intended in any way to limit the description to any spatial or positional orientation. In one example, the terms “top” or “uphole” may be used herein to refer to a direction along the tubing string or component towards the surface. Similarly, the terms “bottom” or “downhole” may be used herein to refer to a direction along the tubing string or component towards the bottom of the well, i.e. away from the surface.

Sliding Sleeve Valve

A sliding sleeve valve according to an aspect of the present description is illustrated in FIGS. 1a to 1c (collectively, “FIG. 1”) and FIGS. 2 to 6. As shown, the sliding sleeve valve 10 comprises a generally tubular body that comprises a first or top sub 12, comprising a box end, and a second or bottom sub 14, comprising a pin end. As would be understood the top sub 12 and bottom sub 14 are designed to connect to adjacent components of a tubing string. For this purpose, the top sub 12 and bottom sub 14 include suitable connecting means for connecting to such adjacent components. For example, each of subs 12 and 14 may, as is common, include threaded portions to form a pin and box connection with adjacent tubular components, other tools, or couplings etc. Although the top sub 12 and bottom sub 14 are described as having box and pin ends, respectively, it will be understood that these ends may be opposite and may be the same or different. The present description is not specific to any particular end configuration.

The sliding sleeve valve 10 also comprises a generally tubular housing, or barrel 16, provided between the top sub 12 and bottom sub 14 and adapted to be connected thereto. As shown in FIGS. 2 to 6, the components of the sliding sleeve valve 10 combine to form the aforementioned generally tubular body, having a bore or lumen 18 extending therethrough.

As shown in FIG. 1, the housing 16 has a first end 20 adapted to connect to the top sub 12 and a second end 22 adapted to connect to the bottom sub 14. In one aspect, each of the first end 20 and second end 22 comprise “box”-type structures, namely, structures having internal threads that are adapted to threadingly engage external threads of the top and bottom subs, respectively. In this way, one end of the top sub 12 is provided within the lumen of the housing 16 to form a first shoulder 24 within the bore 18. Similarly, one end of the bottom sub 14 is provided within the lumen of the housing 16 to form a second shoulder 26 within the bore 18. The purpose of the shoulders 24 and 26 is discussed further below.

The housing 16 includes one or more ports 28 that are provided proximal to one end thereof. As shown in FIGS. 2 to 6, the housing 16 include a plurality of circumferentially arranged ports 28 that are provided proximal to the second end 22 thereof. It will be understood that the present description is not limited to any particular number of ports.

The sliding sleeve valve 10 further comprises a sliding sleeve, or “sleeve” or “piston” 30 slidably provided within the bore of the housing 16. The sliding sleeve 30 has a length defining a first end 32 and a second end 34. As illustrated in FIGS. 2 to 6, travel of the sleeve 30 within the housing 16 is limited by contact between the first shoulder 24 against the sleeve first end 32, or by contact between the second shoulder 26 against the sleeve second end 34.

The sleeve 30 includes a thickened region defining a region of the sleeve 30 having a reduced internal diameter and thereby a radially inward raised profile 36, defined by first and second sleeve shoulders, 38 and 40, respectively. The inward profile 36, and in particular the shoulders 38 and 40, serve as catches by being adapted to engage a shifting tool for effecting movement of the sleeve 30 (as discussed further below). It will be understood that the shoulders 38 and 40 may be provided with a square or angular (i.e. bevelled) geometry to aid in engaging the shifting tool. As noted, the profile 36 preferably has a shorter length than the length of the sleeve 30, thereby resulting in the sleeve 30 having end first and second sections 50 and 52, that extend away from the profile 36. As shown, first end section 50 extends from first shoulder 38 and second section 52 extends from second shoulder 40. This arrangement of the sleeve 30 components results in a functional advantage in that a shifting tool would not need to engage the entire length of the sleeve 30 in order to effect movement of same. This advantage of the sleeve 30 will be more apparent in the following description.

The inner surface of the housing 16 includes a first groove 42 and a second groove 44, each of which is adapted to receive and removably engage a retaining means, such as a snap ring 46 or the like provided on the sleeve 30. The first groove 42 is positioned proximal to the ports 28, while the second groove 44 is positioned axially away from the ports 28, in a direction towards the top sub 12. The snap ring 46 is designed to be biased in a radially outward direction from the sleeve 30 so as to facilitate engagement with one of the grooves 42 or 44 provided on the housing 16. In one preferred aspect, the snap ring 46 may be provided within a recess 48 provided on the outer surface of the sleeve 30. Thus, as would be understood, as the sleeve 30 is axially moved within the housing 16, the snap ring 46 is received within one of the grooves 42 or 44 and an additional force would be required to dislodge the sleeve, where such additional force serves to compress the snap ring 46 thereby allowing disengagement from the respective groove (42, 44).

As shown in FIGS. 2 to 6, the grooves 42 and 44 are adapted to receive the snap ring 46 (or any similar mechanism), and thereby positively locate the sleeve 30 within the housing 16 until a force is applied to move the sleeve to a different axial position. As noted above, the total axial movement of the sleeve 30 within the housing 16 is limited to a region bounded by the first shoulder 24 and second shoulder 26.

It will be understood that, while a snap ring 46 is discussed herein, the retaining means may be any device that functions to retain the sleeve 30 generally in position within the housing 16 when such retaining means is engaged within one of the grooves. As such, the retaining means may comprise a dog, an outwardly biased spring mechanism or any other similar device. Similarly, although grooves 42 and 44 may be a preferred structure, it will be understood that any other means may be used to receive and retain the snap ring 46 or other such retaining means. For example, where, as illustrated, the retaining means comprises a snap ring, a continuous groove may be best to retain the former. If the retaining means comprise dogs or outwardly biased pistons or the like, the groove may alternatively comprise detents or other such structures. The present description is not limited to any particular retaining means. However, for convenience, the term “snap ring” will be used herein in reference to element 46 and the term “groove” will be used in reference to elements 42 and 44.

As illustrated in FIGS. 2 to 4, when the snap ring 46 is received within the first groove 42 of the housing 16, the sleeve 30 is located proximal to the bottom sub 14 and is in a position where it overlaps the ports 28 and thereby closes same. Thus, when the snap ring 46 is retained or received within the first groove 42, the sleeve 30, and therefore the sleeve valve 10, is in the “closed position”, whereby fluid flow through the ports is prevented or at least limited.

As illustrated in FIGS. 5 and 6, when the snap ring 46 is received within the second groove 44, the sleeve 30 is located proximal to the top sub 12 and no longer covers or overlaps the ports 28. Thus, when the snap ring 46 is retained or received within the second groove 44, the sleeve 30, and therefore the sleeve valve 10, is in the “open position”, whereby fluid flow communication between the interior and exterior of the housing 14, through the ports 28, is possible.

As illustrated in FIGS. 2 to 6, the first and second grooves, 42 and 44, provided on the housing 16, are preferably sized to be wider than the snap ring 46. As will be more apparent in the further discussion below, with this arrangement, the snap ring 46 is permitted a limited amount of movement within either of the grooves 42 or 44. This therefore translates to the sleeve 30 being permitted to travel a limited axial distance with respect to the housing 16 while the snap ring 46 is retained in either of the grooves 42 and 44. The widths of the grooves 42 and 44 are sized so that the freedom of movement of the snap ring 46 retained therein allows the sleeve 30 to travel a given distance while still maintaining the sleeve valve 10 in a desired port open or port closed position. For instance, as shown in FIGS. 3 and 4, although the sleeve 30 overlaps, and therefore closes, the ports 28, the snap ring 46 is still able to move within the groove 42 in an axial direction from the bottom sub 14 towards the top sub 12. Similarly, as shown in FIGS. 5 and 6, the valve 10 is maintained in a port open position while the snap ring 46 is able to axial travel within the second groove 44.

As will be appreciated, and according to the preferred aspect described herein, by sizing the grooves 42 and 44 to be wider than the snap ring 46, a functional advantage is realized since, as shown in FIGS. 3 to 6, in order to move the sleeve from the fully closed position, as shown in FIG. 3, to the fully open position as shown in FIG. 6, the sleeve 30 passes through two intermediate stages, which serves to signal to the shifting tool operator that the sleeve has been fully extended or retracted. This signalling feature aids in ensuring that the sleeve is properly shifted into the desired open or closed positions. This is illustrated by the movement of the sleeve 30 from the fully closed position (shown in FIG. 3) to the fully open position (shown in FIG. 6) using a shifting tool (not shown). In particular, once a shifting tool (not shown) is run downhole and actuated to engage the sleeve 30 in the fully closed position, as shown in FIG. 3, the shifting tool is moved axially in an uphole direction, i.e. in a direction from the bottom sub 14 towards the top sub 12. Initially, the operator of the shifting tool will not encounter much resistance as the snap ring 46 travels within the first groove 42. Once the snap ring 46 reaches the end of the groove 42, as illustrated in FIG. 4, further movement of the sleeve 30 is impeded and a greater force is required to axially move the sleeve 30. This increased resistance signals to the operator that the snap ring has reached the upstream end 54 of the groove 42. This position of the sleeve 30 is referred to herein as the “snapped closed”, or intermediary closed position, where the snap ring 46 remains retained within the first groove 42 and the ports 28 remain closed. In order to further advance the sleeve 30 in the upstream direction (i.e. towards the top sub 12), a sufficient tension or force must be applied to the shifting tool to force the snap ring 46 beyond the upstream end 54 of the first groove 42, and thereby out of the groove 42, and to move it towards the direction of the second groove 44. At this point, the operator notices the increase and rapid decrease in the required pulling force required for the shifting tool, signalling that the sleeve 30 has left the “snapped closed” position and is proceeding to the open position. At this point, the ports 28 are not fully open. Subsequently, as illustrated in FIG. 5, the snap ring 46 eventually enters the second groove 44 and the force required to pull the shifting tool reduces. Thus, the operator becomes aware that the sliding sleeve 30 has been moved into the “snapped open”, or intermediary open position. As seen in FIG. 5, in the snapped open position, the ports 28 are open and no longer covered by any portion of the sleeve 30. Further pulling of the shifting tool is possible, in view of the clearance between the width of the groove 44 and the width of the snap ring 46, until the first end 32 of the sleeve 30 abuts the first shoulder 24 of the top sub 12, as illustrated in FIG. 6. At this point, no further axial movement of the sleeve 30 in the uphole direction is possible and the lack of movement of the sleeve 30 and increased force requirement of shifting tool signals to the operator that the sleeve is now in the “fully open” position (FIG. 6). As will be understood, the reverse occurs as the sleeve is moved from the fully open position (FIG. 6) to the fully closed position (FIG. 3).

Thus, as will be understood from the above discussion, an operator of the shifting tool is clearly able to determine when the sleeve 10 is moved from the closed to open or open to closed positions in view of the two-stage signal that is provided. This mitigates against a single signal being misinterpreted as an opening or closing of the sleeve when in reality the sleeve or the shifting tool is simply stuck due to interference with debris or friction etc. As discussed above, when the sleeve valve 10 is used, the operator is clearly advised when the sleeve reaches the fully closed or fully open position. As will be appreciated, the ability of the sleeve valve 10 to effectively signal the open and closed position to the operator is not dependent upon the use of any specific shifting tool. That is, although a preferred shifting tool is described herein, other shifting tools may also be used with the sleeve valve 10 while still providing the same two-stage signalling advantage.

As discussed above, the sleeve valve 10 is provided as an assembly comprising four primary sections: the top sub 12, the bottom sub 14, the housing 16 and the sleeve 30. As will be understood, this offers the advantage that, in assembling the valve 10, the sleeve 30, with the snap ring loaded 46 thereon, can first be inserted into the housing 16 and the top and bottom subs, 12 and 14, can then be attached to the housing 16. As noted above, the opposing ends of the subs 12 and 14, respectively, form the shoulders 24 and 26. In another aspect, one of the top sub 12 or bottom sub 14 may be formed with the housing 16 as a unitary structure. In such case, the aforementioned shoulder 24 or 26 would need to be formed within such structure for the purpose noted above.

As illustrated in FIGS. 2 to 6, and as would be understood by persons skilled in the art, the sleeve valve 10 will include necessary seals to avoid leakage of fluids. For example, one or more seals 58 may be provided at a connection between the top sub 12 and the housing 16. Similarly, one or more seals 60 may be provided at a connection between the bottom sub 14 and the housing 16. Further, seals 62, 64, 66 and 68 may be provided along the length of the sleeve 30 to form seals between the sleeve 30 and the housing 16. In particular, as shown, at least one seal 62 is provided proximal to the first end 32 and at least one seal 68 is provided proximal to the second end 34 of the sleeve 30. Two further seals 64 and 66 are provided at a region corresponding to the profile 36, preferably proximal to the ends thereof.

As would be understood, the seals mentioned above preferably comprise O-rings, which are commonly used for tubing string tools. However, other equivalent sealing devices may also be used as would be apparent to persons skilled in the art. Generally, seals such as those discussed above, are provided in grooves having a depth that is less than the diameter of the seals. As shown in FIGS. 2 to 6, such grooves are provided on the exterior surfaces of the top sub 12, bottom sub 14 and sleeve 30, as is typical.

In one aspect, the edge 24 of the top sub 12 is preferably provided with a bevel 70 directed away from the sleeve 30. Similarly, the edge 26 of the bottom sub 14 is preferably provided with a bevel 72 also directed away from the sleeve 30. As discussed further below, the bevels 70 and 72 aid in disengaging the shifting tool from the sleeve 30.

Shifting Tool—Sleeve Engagement Portion

In one aspect, the present description provides a shifting tool for moving a sliding sleeve, such as, but not limited to, sleeve 30 of sleeve valve 10 discussed above. Thus, such shifting tool is used to open and/or close ports provided on the sleeve valve, such as ports 28 discussed above. As will be understood by persons skilled in the art, shifting tools as described herein are generally adapted to be inserted through the tubing string to the location of a selected sleeve valve, where they are actuated and thereby act upon the sleeve to move it axially with respect to the tubing string. This movement of the sliding sleeve was illustrated in the description above. Typically, shifting tools are run in the tubing string from surface using a work string, such coil tubing and the like. The shifting tools are therefore adapted to be connected to a work string and, optionally, to be connected to other work string components (such as other tools etc.)

A shifting tool according to an aspect of the present description is shown in FIGS. 7 to 9. As shown, the shifting tool 100 comprises a generally cylindrical and elongate body, with a longitudinal axis, and having a top end 102, which, when in use, faces in the uphole direction, and a bottom end 104, which, when in use, faces in the downhole direction. As shown in FIG. 9, the top end 102 includes a box portion 106 having an internal thread. The bottom end 104 includes a pin portion 108 having an external thread. As will be understood, the box portion 106 is adapted to threadingly engage a pin portion of a work string (e.g. coil tubing) component, while the pin portion 108 is adapted to threadingly engage a box portion of another work string component. It will also be understood that the box and pin portions mentioned above may also be reversed or the shifting tool 100 may be provided with two box or two pin portions. In the latter instance, it would be common for the shifting tool to be connected to at least one coupling or the like. It will also be understood that in some instances the shifting tool 100 may form the bottom or terminal end of a work string, in which case the pin portion 108 may comprise some other configuration.

In a preferred aspect, the shifting tool 100 comprises an assembly of a number of tubular components, or “subs”, joined together in a known manner. For example, as shown in the accompanying figures, the shifting tool 100 may comprise a driver sub 110, a mid sub 112, a retainer sub 114 and a sleeve engagement sub 116. It should be noted that the nomenclature used for these tubular components is not intended to limit the scope of the description in any way. The functions of these subs are discussed further below.

The top end of the shifting tool 100 may comprise a top crossover sub 118 and the bottom end of the shifting tool may comprise a bottom crossover sub 120. As will be understood, and as shown in the accompanying figures, the top and bottom crossover subs, 118 and 120, provide the box and pin means, respectively, for connecting the shifting tool 100 to other components of the work string. The individual subs of the shifting tool 100 may be secured together in a variety of ways. In the aspect shown in the present figures, this is achieved using a number of set screws, such as those shown at 122, and/or pins, such as those shown at 124. The top crossover sub 118 would be generally open to the lumen of the coil tubing or other component of the work string (not shown).

The shifting tool 100 comprises a number of sleeve engagement arms which, as described below, are adapted to engage a sliding sleeve such as sleeve 30 described above when the shifting tool is actuated. As illustrated for example in FIG. 11, the shifting tool 100 according to one as aspect as described herein preferably includes two, i.e. first and second, sleeve engagement arms shown at 126 and 128, which, in a preferred aspect, are generally circumferentially equidistantly spaced apart. Thus, in one aspect as illustrated, the first and second sleeve engagement arms 126 and 128 are circumferentially spaced apart by 180 degrees over the circumference of the shifting tool 100. It will be understood from the present description that such circumferentially equidistant spacing is preferable for engaging a sleeve but that such spacing is not essential. Any other spacing or arrangement will be apparent to persons skilled in the art. As will be understood, the present description is also not limited to only two sleeve engagement arms and any number of such arms may be provided. For the present purposes, two arms may be suitable in view of diameter restrictions on the shifting tool 100. Thus, for larger diameters, more than to of the sleeve engagement arms may be provided.

Each of the sleeve engagement arms 126 and 128 include a pair of sleeve engagement fingers, axially spaced apart on each respective arm. In one aspect, each pair of sleeve engagement fingers is provided generally at opposite ends of the respective sleeve engagement arm. For instance, as illustrated in the accompanying figures, first and second sleeve engagement arms 126 and 128 each include respective first sleeve engagement keys, or fingers 130 and 134, provided at the “top” or uphold ends of arms 126 and 128, proximal to the retainer sub 114. The sleeve engagement arms 126 and 128 also include respective second sleeve engagement keys, or fingers 132 and 136, which are provided at the “bottom”, or downhole end of the arms, axially spaced apart from the first sleeve engagement fingers in a direction towards the bottom crossover sub 120. As shown, the first sleeve engagement fingers, 132 and 136, are generally on a common transverse plane, whereby the fingers are generally at the same axial distance along the length of the shifting tool 100. The second sleeve engagement fingers 132 and 136 are similarly arranged. In this way, and as illustrated for example in FIGS. 13, 15, 17, and 19-21, a sleeve engagement space is formed between the respective first and second fingers. This arrangement will be more apparent in the description provided below.

The sleeve engagement arms 126 and 128 are connected to the shifting tool 100 by hinges so as to allow the arms to be radially extended. In particular, first sleeve engagement arm 126 is attached to the shifting tool 100 by means of hinges 138 and 140 and the second sleeve engagement arm 128 is attached to the shifting tool 100 by means of hinges 142 and 144. As shown in the accompanying figures, the hinges 138, 140, 142, and 144 allow the arms 126 and 128 to be radially extended away from the longitudinal axis of the shifting tool 100. In particular, and as illustrated, the hinges allow the arms 126 and 128 to swing about an axis that is at least generally parallel to the longitudinal axis of the shifting tool 100. By way of example, FIGS. 13, 14, and 19 show the shifting tool 100 with the arms 126 and 128 in the retracted position, whereas FIGS. 15, 16, and 20 show the arms 126 and 128 in the extended position. The hinges 138, 140, 142, and 144 may be of any structure that allows the arms 126 and 128 to swing in the manner described above. For example, as shown, the hinges may be formed by providing a slot in each of the arms 126 and 128 for receiving a respective tongue provided in a non-moving portion of the shifting tool 100. A dowel pin or other similar retaining means may be provided through the slot and through the tongue to allow the two portions to swivel with respect to each other.

The first and second sleeve engagement arms 126 and 128 are also associated with a first actuating mechanism for effecting the aforementioned extension and retraction. In particular, and according to one aspect, the first sleeve engagement arm 126 includes first and second links 146 and 148 generally provided in a spaced apart manner along the length of the arm 126. Similarly, the second sleeve engagement arm 128 includes first and second links 150 and 152 that are also generally provided in spaced apart manner along the length of the arm 128. As shown, for example, in FIGS. 19, 20 and 21, the links, 146, 148, 150, and 152 have a first end connected to the respective arm, 126 or 128. The opposite ends of the links 146, 148, 150, and 152 are connected to respective knuckles, wherein link 146 is connected to knuckle 154, link 148 is connected to knuckle 156, link 150 is connected to knuckle 158, and link 152 is connected to knuckle 160. Both ends of the links 146, 148, 150, and 152 are connected in a moveable manner whereby, as shown, the ends of the links are rotatable about an axis that is generally parallel to the longitudinal axis of the shifting tool 100. For this purpose, the ends of the links may be connected to the respective arms, 126 or 128, or the respective knuckles, by means of dowel pins, screws, or any other similar mechanism that would allow for the aforementioned movement. By way of example, as shown in FIG. 11, a first end of link 146 is connected to the knuckle 154 by means of a machine screw 162 and the second end of link 146 is connected to the first sleeve engagement arm 126 by means of machine screw 164. The other links, 148, 150, and 152 are preferably connected in a similar manner.

The knuckles 154, 156, 158, and 160 are connected to a first rotating mandrel 166 that is provided within the sleeve engagement sub 116 and which extends longitudinally therein. The first rotating mandrel 166 generally comprises a tubular body having a longitudinal axis that is generally parallel with, and preferably coaxial with, the longitudinal axis of the sleeve shifting tool 100. The first rotating mandrel is also adapted to rotate about its longitudinal axis within the sleeve engagement sub 116 and with respect to both the sub 116 and the sleeve shifting tool 100 itself. However, the first rotating mandrel 166 is fixed in position axially within the shifting tool 100.

The knuckles 154, 156, 158, and 160 are functionally connected to the first mandrel 166 in such a manner that rotation of the first mandrel 166 about its longitudinal axis (i.e. axial rotation) imparts a circumferential force on the knuckles. For this purpose, and as shown in FIG. 11, the first mandrel 166 may be provided, at least at certain locations, with a profiled outer surface, such as a hexagonal or octagonal profile. The knuckles in turn may be provided with a connecting ring, such as connecting ring 168 provided on knuckle 154, wherein the connecting ring has a complementary inner profile and is adapted to fit over the first mandrel 166, to form an interlocking arrangement there-between. As will be understood, with this arrangement, once the connecting ring 168 is provided over the first mandrel 166, the complementary profiles prevent relative rotation there-between. Further, with this arrangement, upon rotation of the first mandrel 166, a rotational force will be imparted to the connecting ring 168 and, in the result, a circumferential force is applied to the link 146. It will be appreciated that while the aforementioned hexagonal outer profile and connecting ring arrangement may be preferred in terms of ease of assembly (since the various components can be inserted over others), the knuckles may be connected to the first mandrel in any other means for achieving the same result. For example, the connecting rings may be secured to the first mandrel 166 to achieve the same result, without the need to provide the aforementioned complementary profiles. Alternatively, the mandrel may be provided with a number of keys on the outer surface thereof and the ring may be provided with complementary grooves to receive such keys. All of the knuckles described above may be connected to the first mandrel 166 in the same manner as knuckle 154.

FIG. 11 also illustrates another preferred aspect, wherein both of knuckles 154 and 158, associated respectively with the first and second sleeve engagement arms 126 and 128, are connected to a common connecting ring 168. As will be appreciated, in this way, rotation of the first mandrel 166 imparts simultaneous rotational force against both of knuckles 154 and 158. In a similar manner, the knuckles 156 and 160 may also be connected to a common connecting ring 170, in turn connected to the first mandrel 166. While the use of a common connecting ring for two knuckles is described, it will be appreciated that the same simultaneous rotational force from the first mandrel 166 can be transmitted in any other manner. For example, the knuckles may comprise separate connecting rings, or other such connecting means, wherein the adjacent connecting means are joined or secured together. As will be appreciated, the present description is not restricted to any particular force translating mechanism between the first rotating mandrel and the knuckles.

As discussed above, upon rotation of the first rotating mandrel 166, a rotational force is applied to connecting rings attached to the knuckles and, in turn, this is translated to a circumferential force that is applied to the links 146, 148, 150 and 152. The links in turn transmit this circumferential force to the first and second sleeve engagement arms 126 and 128. As will be understood, since the forces applied to the arms 126 and 128 stem from the rotation of the first mandrel 166, such forces would ultimately be generally equal. In other words, with this above-described arrangement a generally equal circumferential force is applied to both sections of the arms 126 and 128 connected to the respective links and, moreover, such force is applied simultaneously.

As the circumferential force is applied to the arms 126 and 128, circumferential movement of the arms is inhibited by the respective hinges, 138, 140 and 142, 144. As a result, the unhinged portions of the arms 126 and 128, that is, the portions having the fingers 130, 132, 134, and 136, are extended radially outward as illustrated, for example, in FIGS. 13 to 17. In particular, this radially outward movement results in the radially outward extension of the fingers 130, 132, 134, and 136, thereby resulting in the extended position of the arms are shown in FIGS. 15 and 16, for instance. This position may be referred to also as the extended, or sleeve engagement position, of the shifting tool 100, as discussed below.

As shown in FIGS. 9 and 10, a bottom end of first rotating mandrel 166 (that is, the end adjacent the bottom end 104 of the shifting tool 100) of the sleeve engagement sub 116 extends partially into a hub 172 provided on the bottom crossover sub 120. The bottom crossover sub 120 is connected to the sleeve engagement sub 116 and is maintained stationary with respect to same. To allow rotation of the first rotating mandrel 166 within the bottom crossover sub 120, the hub 172 is provided with a bearing means, as would be known to persons skilled in the art. For example, such bearing means may comprise a number of ball bearings 174 provided within a groove or other known ball bearing retaining means that would be known to persons skilled in the art. As will be understood, the ball bearings facilitate rotation of the first rotating mandrel 166 within the hub 170. It will also be understood that any number of seals, such as O-rings 176, as shown in FIGS. 9 and 10 may be employed to establish a fluid seal between the bottom crossover sub 120 and the sleeve engagement sub 116. It will be understood that similar seals may be employed between other sections of the shifting tool 100.

As shown in FIGS. 9 and 10, a top end of the first rotating mandrel 166 (that is, the end adjacent the top end 102 of the shifting tool 100) extends through the retainer sub 114 and into the mid sub 112. The first rotating mandrel 166 is allowed to rotate with respect to both the retainer sub 114 and the mid sub 112. In this regard, one or both of the retainer sub 114 and mid sub 112 may be provided with a bearing means for allowing rotation of the first mandrel 166 therein. In one example, the bearing means may comprise a number of ball bearings such as shown at 178 and/or roller bearings such as shown at 179. Various other bearing means will be known to persons skilled in the art.

As will be understood, the present description is not limited to any particular means for retaining the first rotating mandrel 166 is the desired position and for allowing rotation of same within the sleeve shifting tool 100.

Shifting Tool—Actuating Portion

As mentioned above, actuation of the shifting tool 100 into the extended position is achieved by rotation of the first mandrel 166. As discussed below, such rotation of the first mandrel 166 is caused by the action of the driver sub 110, which is shown in detail in FIGS. 9, 10, 13, 15, and 17. As shown, a bottom end of the driver sub 110 is connected and secured to a top end of the mid sub 112. In one aspect, the top end of the mid sub is provided within the lumen of the driver sub 110 so as to form a shoulder 180 therein. The connection between the driver sub 110 and the mid sub 112 may be preferably sealed using any known means. For example, one or more O-rings 182 may be utilized for forming the seal(s) between the sub 110 and sub 112.

The driver sub 110 generally comprises a cylindrical barrel having a bore generally coaxial with the shifting tool 100. Within the bore of the driver sub 110 is provided a generally cylindrical insert 184, which is provided proximal to a top end of the driver sub 110, that is, the end of the driver sub 110 proximal to the top end 102 of the shifting tool 100. The insert 184 is secured in place within the driver sub 110 and prevented from moving axially therein. The insert 184 comprises a bore that is coaxial with the bore of the driver sub 110, wherein the insert 184 has a top end that opens to the lumen of the top crossover sub 118 and thereby into the lumen of the coil tubing or other work string. The insert also includes a bottom end 186 having a reduced internal diameter, forming a shoulder within the bore of the insert 184. A first piston 188 is provided within the insert 184 and is reciprocally slidable therein. The first piston 188 has a body that extends through the bottom end 186 of the insert 184 and a top end 190 that is provided proximal to the top end of the insert 184. The top end 190 of the first piston 188 has an external diameter that is greater than the internal diameter of the bottom end 186 of the insert 184. Thus, as shown for example in FIGS. 13, 15, 32, and 33, although the body of the first piston 188 is able to move axially and reciprocally with respect to the insert 184, axial movement of the first piston 188 in a direction from the top end to the bottom end of the shifting tool 100 is inhibited upon the top end 190 of the first piston 188 contacting the bottom end 186 of the insert, which is the position illustrated in FIG. 15.

The driver sub 110 further includes a second piston 192 comprising a generally cylindrical body having a top end and a bottom end and a bore extending there-through. The top end of the second piston 192 comprises radial flange 194 defining a region reduced internal diameter. As can be seen in FIGS. 10, 13, 15, and 17, for example, the body of first piston 188 is slidably provided within bore of the second piston and the bottom end of the first piston is provide with a radial flange 196 defining a region of the body of the first piston having a larger outer diameter. As shown, the outer diameter of the flange 196 of the first piston 188 is greater than the inner diameter of the flange 194 of the second piston 192. In this way, axial separation of the first piston and second piston is prevented.

The driver sub 110 further includes a second rotating mandrel 198 provided proximal to the bottom end thereof. One aspect of the mandrel 198 is illustrated in isolation in FIGS. 36 and 37. As with the first rotating mandrel 166, the second rotating mandrel also comprises a generally tubular body having a longitudinal axis that is generally in line with the longitudinal axes of the first rotating mandrel 166 and the driver sub 110 (i.e. of the shifting tool 100). The second rotating mandrel 198, as with the first rotating mandrel 166, is axially fixed in position within the shifting tool 100, although the second rotating mandrel 198 is allowed to rotate about its longitudinal axis. The bottom end of the second rotating mandrel 198 is connected to the top end of the first rotating mandrel 166, whereby rotation of one of the mandrels results in a corresponding rotation of the other mandrel. As will be discussed further below, when in use, the second rotating mandrel 196 generally drives the rotation of the first rotating mandrel 166. As will be understood, the link or connection between the two mandrels, 166 and 198, may take any form as known in the art to achieve this purpose. In one aspect, as illustrated in FIGS. 9 and 10, the two mandrels may be linked in a box and pin arrangement and secured to each other using a set screw, such as 200, a pin or any other such connection means. It will be understood that the present description is not limited to any particular means for connecting the mandrels 166 and 198 together.

The top end of the second rotating mandrel 198 is received within the lumen of the second piston 192. For this purpose, the bottom end of the second piston 192 may be provided with a flange 202 that has an outer diameter that is adapted to slidably contact the bore of the driver sub 110 to provide stability. The flange 202 has an inner diameter that slidably contacts the second rotating mandrel 198 and allows rotation of the second mandrel 198 therein.

The bottom end of the second piston 192 is also provided with one or more (i.e. at least one) guide pins 204 that are fixed in position with respect to the second piston 192. In this regard, the guide pins 204 may be received within apertures 205 or other such openings provided on the outer surface of the second piston 192. The guide pins 204 are adapted to be received within corresponding spiral or helical grooves 206 provided on the outer surface of the second rotating mandrel 198 and at the top end thereof. As will be understood, at least one guide pin 204 will be provided for each groove 206. In view of this arrangement, as the second piston 192 is axially advanced towards the bottom end of the shifting tool, it will be understood that the guide pins 204, engaged within the grooves 206, will impart a rotational force on the second rotating mandrel 198 as they are moved along the respective groove. It will be understood that, for this purpose, the second piston 192 is arranged so as to be incapable of axial rotation while being axially advanced within the driver sub 110. In one aspect, the reciprocal stroke of the second piston 192 may be constrained by a groove or track etc. (not shown) provided in wall of the driver sub 110, in which case the second piston 192 may be provided with a suitable key or the like (not shown) to engage the groove or track.

The second rotating mandrel 198 is illustrated in isolation in FIGS. 36 and 37 so that the grooves 206 can be more easily seen. In the aspect shown, the mandrel 198 is provided with three generally helical grooves 206 that are generally circumferentially equidistantly spaced. As discussed above, in a preferred aspect, at least one guide pin 204 is provided to engage with a respective groove 206. Thus, for the version illustrated in the present figures, since three grooves 206 are provided, there would preferably be at least three guide pins provided as well. In the aspects illustrated in previous figures, the second rotating mandrel 198 has a solid wall without any opening there-through. In the aspect illustrated in FIGS. 36 and 37, the second rotating mandrel 198 includes optional apertures 240 extending through the body of the mandrel 198. These apertures are believed to improve the flow dynamics of the fluid flowing through the tool and aid in maintaining the tool in the desired actuated state.

Axial movement of the second piston 192 in the direction towards the bottom end 104 of the shifting tool 100 is limited by a flange 208 provided within the lumen of the driver sub 110. As shown for example in FIG. 15, the inner diameter of the flange 208 of the driver sub 110 is a smaller than the outer diameter of flange 194 provided on the top end the second piston 192. As such, axial movement of the flange 194 beyond the flange 208 of the driver sub 110 is prevented. While the term flange has been used herein, it will be understood that such flanges are not necessarily continuous and may comprise a number of radial protrusions.

Both the first piston 188 and the second piston 192 are biased in a direction towards the top end 102 of the shifting tool 100. In one aspect, such biasing is achieved by means of springs. As illustrated, a first spring 210 serves to axially bias the first piston 188 and a second spring 212 serves to axially bias the second piston 192. The first spring 210 is provided between the top end 190 of the first piston 188 and the radial flange 194 provided at the top end of the second piston 192. Thus, the first spring 210 axially biases the first piston 188 away from the second piston 192. As also shown in the accompanying figures, the first spring 210 may be provided coaxially over the body of the first piston 188. The second spring 212 is provided between the flange 202 of the second piston 192 and the shoulder 180 of the mid sub 112. Thus, the second spring 212 axially biases the second piston 192 away from the mid sub 112. Although reference is made herein to “springs”, persons skilled in the art will understand that any other biasing means may be used to achieve the same purpose, such as hydraulic systems etc. Springs, such as coiled springs, are however preferred given the geometries of the tool.

In view of the above description, it will be appreciated that as the first piston 188 is advanced towards the bottom end 104 of the shifting tool 100, it applies an axial force on the second piston 192, which in turn is advanced towards the bottom end 104. In view of the engagement between the guide pins 204 of the second piston 192 and the grooves 206 of the second rotating mandrel 198, it will be understood that such axial advancement of the second piston 198 imparts a rotational force on the second mandrel 198. Rotation of the second mandrel 198 in turn results in axial rotation of the first rotating mandrel 166. As discussed above, rotation of the first rotating mandrel 166 causes the sleeve engagement arms 126 and 128 to be extended, whereby the shifting tool 100 is actuated into the extended, or sleeve engaging position. The movement of the aforementioned components is illustrated by comparing FIGS. 13 and 15 or in FIGS. 19 and 20, for example.

Although the present description refers to two separate mandrels 166 and 198 that are connected together, it will be understood that the shifting tool described herein may also comprise a single mandrel having the features of the two aforementioned mandrels incorporated therein. The use of two mandrels may be preferred for ease of assembly.

For advancing the first piston 188, and thereby actuating the shifting tool 100, hydraulic pressure may be applied from surface through the coil tubing or other work string components to which the shifting tool 100 is attached. For this purpose, the first piston 188 is provided with a top, or uphole facing piston head 214 that is sealed against the insert 184 (as discussed further below). The piston head 214, and therefore the first piston 188, is adapted to be advanced axially towards the bottom end 104 of the shifting tool 100 once a sufficient pressure is applied through the work string to overcome the biasing force of the second spring 212. In the result, the sleeve shifting tool 100 is put into the extended state as shown for example in FIG. 15. Once the pressure is released, the second spring 212 forces the shifting tool 100 to return to the retracted position as shown for example in FIG. 13.

The piston head 214 is shown in more detail in FIGS. 32 and 33. As shown, the piston head comprises an opening in the top end of the first piston 188. Within the opening is positioned a nozzle 226 for providing a restriction to the flow of fluid through the shifting tool 100. The nozzle 226 is received within a recess 225 provided at the top of the first piston 188 and is held in position with a retaining means, such as a snap ring 227 or the like. The nozzle is sealed against the wall of the recess 225 by means of a resilient seal 229, which may for example comprise an O-ring or the like. As illustrated in FIGS. 32 and 33, the seal 229 is preferably retained within a groove provided on the outer surface of the nozzle 226.

In one aspect, the nozzle 226 comprises an orifice plate as shown in FIGS. 32 and 33 (and earlier figures), which is commonly known. As would be understood, as pressure is increased in the work string (e.g. the coiled tubing) to which the shifting tool is attached, such pressure acts upon the orifice plate nozzle 226 and imparts a downward force thereon. When such force exceeds the biasing force of the spring 212, movement of the first piston 188 results.

FIGS. 34 and 35 illustrate another aspect of the nozzle described above. In this aspect, the nozzle, shown as 226 a, comprises an elongated body having a passage extending therethrough that has a converging-diverging geometry. As shown in FIGS. 34 and 35, this aspect of the nozzle, 226 a, has an inlet 230 and an outlet 232. Proximal to the inlet is provided a throat 228, which forms a constriction in the passage. In this way, the passage between the inlet and the throat reduces in diameter thereby forming a converging section. Downstream of the throat 228, the diameter of the passage gradually expands, forming the diverging portion of the passage. The geometry of the nozzle 226 a is believed to reduce the turbulence of fluid flowing therethrough and thereby achieve more predictable actuation of the shifting tool when needed. FIGS. 34 and 35 also illustrate, at 231, a groove, as described above, provided on the outer surface of the nozzle for retaining a seal 229. As would be understood, a nozzle such as 226 a may require a larger recess 225 in first piston 188. Such accommodations would be understood by persons skilled in the art.

As mentioned above, the first piston 188 is preferably sealed against the insert 184. Such seal is illustrated in FIGS. 32 and 33, for example, at 234 and 236, which, in one aspect, comprise resilient seals, such as O-rings, that are provided on the outer surface of the first piston. As will be understood, seals such as 234 and 236 serve to ensure that fluids passing through the work string are diverted through the nozzle alone. As would be known in the art, seals 234 and 236 are retained within respective grooves provided on the outer surface of the first piston 188, as shown in FIGS. 32 and 33.

Similarly, a seal, such as shown at 238 is provided between the insert 184 and the inner surface of the driver sub 110.

In one aspect, the shifting tool 100 may optionally include a filter 216 or the like to prevent debris etc. from entering the shifting tool 100. As noted, only certain figures, such as FIGS. 10, 13, 15, and 17, illustrate this optional aspect of the description. FIGS. 9, 19, 20, and 21, for example, illustrate the same shifting tool 100 without the optional filter 216.

Operation of Shifting Tool

In operation, the sleeve shifting tool 100, in the retracted state, is run down-hole and positioned at a region where a sliding sleeve valve is located and where such valve is to be manipulated into an open or closed position. The shifting tool in this retracted state is shown for example in FIGS. 13, 19, and 30. When positioned in the desired location, the shifting tool 100 is actuated by increasing pressure as described above, and the arms 126 and 128 are thereby extended into the extended state as shown for example in FIGS. 15, 20, and 31. In the extended state, the shifting tool 100 is able to engage a sliding sleeve within the sleeve engagement space formed between the pairs of keys, or fingers (i.e. 130 and 132, and 134 and 136), provided on the arms 126 and 128. It will be understood that for such engagement to occur, the sleeve being shifted would include some engagement means provided thereon. In one example, the sleeve may have a smaller internal diameter than the housing carrying the sleeve. In such case, the opposed ends of the sleeve would extend into the lumen of the sleeve valve and would therefore provide surfaces that can be engaged within the sleeve engagement space of the shifting tool 100, as described above. A sleeve of this type is described, for example, in U.S. Pat. No. 9,638,003. Thus, the shifting tool described herein may be applied to known sleeve valves.

Once the sleeve shifting tool 100 is actuated and engages a sliding sleeve, the shifting tool 100 is advanced axially towards the top 102 or bottom 104 directions. Once the sleeve encounters a limiting means, such as a shoulder provided on the sliding sleeve valve, further advancement of the shifting tool 100 forces the arms 126 and 128 inwards in a direction towards the retracted state. However, such inward force applied to the arms 126 and 128 would be counteracted by the hydraulic pressure applied to the tool 100. To accommodate such further advancement, the first spring 210 allows the second piston 198 to be axially advanced towards the first piston 188, to thereby result in the shifting tool being placed into a “back driven” position as illustrated in FIGS. 17 and 21. As will be understood, in this position, the shifting tool 100 may be axially moved to the location of a further sliding sleeve valve, at which point, the tool 100 will automatically return to the extended position to allow engagement with another sliding sleeve. Thus, a series of sliding sleeves may be opened or closed without adjusting the pressure applied to the shifting tool 100.

To assist the movement of the sleeve shifting tool 100 from one sliding sleeve valve to another, the fingers of the sleeve engagement arms 126 and 128 are preferably provided with bevels facing the top 102 and bottom 104 ends of the shifting tool. For example, the fingers 130 and 134, provided on the top ends of the sleeve engagement arms 126 and 128, are preferably provided with respective bevels 218 and 220. Similarly, fingers 132 and 136, provided on the bottom ends of the sleeve engagement arms 126 and 128, are preferably provided with respective bevels 222 and 224.

As will be understood, when the sleeve shifting tool 100 is moved to the back-driven position, the added force required to axially advance the shifting tool 100 would be sensed by the operator at surface. This would therefore signal to the operator that the shifting tool 100 is being moved between sleeve valves.

Combination of Sleeve Shifting Tool and Sliding Sleeve Valve

The combination of the sleeve shifting tool 100 and the sliding sleeve valve 10 described herein offers a unique advantage over known sleeve shifting apparatuses. In particular, the present description provides a sliding sleeve valve 10, such as that described above, wherein an internal profile 36 is provided on the sleeve 30, and a shifting tool 100 that is adapted to engage such profile.

Referring to FIGS. 22 and 26, the sleeve shifting tool 100 is shown in its retracted position and in a position adjacent a sliding sleeve valve 10. As will be understood, the portion of the tubing string illustrated in these figures is provided in a horizontal well and, therefore, the shifting tool 100, having a smaller diameter than the lumen of the valve 100, typically rests on the lowermost portion thereof. FIG. 22 also illustrates a preferred aspect of the present description wherein the sleeve engagement space, formed between the respective fingers of the sleeve engagement arms 126 and 128, is longer than the length of the profile 36. As will be understood, this respective configuration assists in positioning of the shifting tool 100 in the required position. That is, since the engagement space for the sleeve is larger than the profile 36, a degree of clearance is permitted between the relative position of the shifting tool 100 and the sleeve 30. This feature will be more apparent in the following description.

FIGS. 23 and 27 illustrate the sleeve shifting tool 100 in its extended position (i.e. the position shown in FIG. 16). As discussed above, this position of the shifting tool 100 is achieved by applying hydraulic pressure to the work string to which the shifting tool 100 is attached and thereby actuating the shifting tool as discussed above. As can be seen, the shifting tool 100 may be positioned at a general location near the profile 36 and actuated so as to extend the fingers 130, 132, 134, and 136 of the sleeve engagement arms 126 and 128 so that the pairs of fingers 130, 132 and 134,136 are provided on opposite ends of the profile 36 of the sleeve 30. This is referred to herein as the extended or sleeve engagement position of the tool 100. As discussed above, the sleeve engagement space between the respective pairs of fingers is longer than the profile 36 and, as such, the tool 100 does not need to be positioned with a high degree of accuracy. After actuation, the sleeve shifting tool is moved until the one of the sets of fingers engages a shoulder of the profile 36. In the example illustrated in FIGS. 23 to 25 and 27 to 29, the sleeve 30 is being shifted in the up hole (or top 102) direction in order to open the ports 28 on the sliding sleeve valve 10. Thus, after actuating the shifting tool 100, and engaging the profile 36 of the sleeve within the sleeve engagement space, the shifting tool 100 is moved in the up-hole direction until the fingers 132 and 136 contact the bottom facing shoulder 40 of the profile 36. This position is shown in FIG. 23, which also shows the snap ring 46 engaged within first groove 42 of the sleeve valve 10. Subsequently, the sleeve shifting tool 100 is urged in the up-hole direction by applying increasing force until the snap ring 46 is force into the recess 48 provided in the sleeve 30, as described above. Pulling of the shifting tool 100 is continued until the snap ring 46 enters into the second groove 44. At this point, the operator senses a reduction in the pulling force require to move the shifting tool 100. As described above, this position is referred to as the “snapped open” position and is illustrated in FIG. 24. Further advancement of the sleeve 30 is permitted in the up-hole direction owing to the width of the second groove 44, as also discussed above.

When the shifting tool 100 is advanced further up hole, the bevels 218 and 220 on the fingers 130 and 134, respectively, contact the bevel 70 provided on the top sub 12 of the sleeve valve 10. At this point, further advancement of the shifting tool 100 requires additional force in order to compress the second spring 212 and thereby force to shifting tool 100 into the back-driven position. Such additional force requirement is sensed by the operator. This event also signals to the operator that the sleeve valve 10 has entered into the fully open state and that the shifting tool 100 is being moved away from the sleeve valve 10 and towards an adjacent sleeve valve. The sensed force will be reduced when the shifting tool is returned to the extended position, which occurs when the profile of the adjacent sleeve enters into the sleeve engagement space of the shifting tool 100.

As will be understood, and as discussed above, the shifting tool 100 could also be used to move the sleeve 30 from the open to the closed port position using the shifting tool 100 by moving such tool in the opposite direction.

Indexing Tool

In certain applications, and particularly in the case of horizontal wells, it is common for the interior of the tubing string to contain sand and/or other debris from the formation. In such case, the operation of known shifting tools in often impaired by the debris interfering with the engagement between the shifting tool and the sliding sleeve. As many of the shifting tools are run in with coiled tubing, it is often difficult to reposition the shifting tools to achieve the desired engagement. In such cases, the desired sleeve is either not actuated or the work string is withdrawn and repositioned. As will be understood, this results in considerable delays and added expense to the well operations.

As would be understood, the shifting tool described herein provides an improved design over known tools that allows an operator to more accurately engage and move a desired sleeve. However, if the amount of debris in the tubing string is great, the operation of the presently described shifting tool may also be impaired. For example if a sufficient amount of debris is collected on the bottom of the tubing string at the region of a sliding sleeve, some of the keys or fingers, 130 to 136, described above may be blocked from engaging the sleeve.

To address the above-mentioned issue, the present description provides an indexing tool that allows a shifting tool to be axially rotated while in situ, thereby allowing a unique means of repositioning the shifting tool without extracting the work string from the tubing string.

FIG. 38 illustrates the shifting tool 100 described above, where like elements are identified with like reference numerals. The shifting tool 100 is connected to other elements of the work string, some of which are illustrated. In particular, at the uphole end of the shifting tool, there is provided a swivel body 400 that is connected to the top crossover sub 118. As would be known to persons skilled in the art, a swivel sub permits axial rotation of a string component. In the present case, the swivel sub 400 serves to permit the shifting tool to rotate about its longitudinal axis with respect to the uphole portion of the work string. The purpose of this rotation is described further below.

Downhole of the shifting tool 100 is provided an indexing tool 402, which comprises a main body 404, comprising a generally tubular housing for the internal components of the indexing tool 402, as discussed below. The indexing tool 402 may also optionally be accompanied by an upper drag block body 406, positioned uphole of the main body 404, and/or a lower drag block body 408, positioned downhole of the main body 404. Drag block bodies are generally known in the art and serve to act as anchors for the string. For this purpose, the drag block bodies are provided with drag block, such as shown at 410 and 412. Slips, such as shown at 414 may also be provided with the drag block bodies.

In one aspect, the indexing tool may also optionally be associated with a packer such as shown at 416. In one aspect, the packer 416 is axially located uphole of the indexing tool 402 and downhole of the shifting tool 100.

The shifting tool is provided with an intermediary sub 418 connected to the downhole end of the shifting tool 100, and more particularly to the bottom crossover sub 120. The intermediary sub 418 is connected to the shifting tool 100 so as to avoid relative axial rotation therebetween.

As more clearly shown in FIG. 39, a mandrel 420, which forms a component of the indexing tool 402, is connected to the intermediary sub 418 and, as with the shifting tool 100, in such a manner as to prevent relative axial rotation therebetween. In this regard, the mandrel 420 may be connected to the intermediary sub 420 by a locking nut or pin 422. The mandrel comprises a generally elongate tubular body that extends through the length of the indexing tool 402.

FIGS. 40 and 41 illustrate the indexing tool 402 in cross-sectional views. As shown, the indexing tool comprises the mandrel 420 that is provided generally coaxially within the main body 404. As noted above, the uphole end of the mandrel 420 is connected in a generally fixed manner to the shifting tool 100. The downhole end of the mandrel is provided with a “J” barrel 424. The mandrel 420 and J barrel are connected in a generally coaxial manner and also in such a manner as to prevent relative axial rotation therebetween. In one aspect, the downhole end of the mandrel 420 is provided with a threaded pin portion, which is adapted to be threadingly engaged within a correspondingly threaded box portion of the J barrel. This is further illustrated in FIG. 42, where the threaded box of the J barrel 424 is illustrated at 426.

The J barrel comprises is provided with a series of slots, commonly referred to as “J” slots, on the outer surface thereof. The J slots are designed to cooperate with a lug ring 428 as shown in isolation in FIG. 43. The lug ring 428 is immovably secured to the housing 404, such as by welding or other such means. The lug ring 428 comprises one or more internally extending lugs 430. As will be explained, the number of lugs 430 corresponds to the number of J slots provided on the J barrel.

In FIG. 42, the J barrel 424 is illustrated in one aspect as having three longitudinally extended first slots 432. The slots are generally equidistantly provided over the circumference of the J barrel 424. Thus, in the aspect illustrated, each first slot 432 is separated by 120° from the adjacent first slot. As shown, the first slots 432 extend from the uphole end 434 of the J barrel and approach the downhole end 436 thereof. The downhole end 436 of the J barrel comprises a series of shorter second slots 438 extending towards the uphole end 434 of the J barrel and generally parallels to the first slots 432, but only extending partially along the length of the J barrel, as illustrated in FIG. 42. The second slots 438 are also equidistantly provided over the circumference of the J barrel. The number of the second slots 438 corresponds to the number of first slots 432. Thus, in the aspect shown, three second slots 438 are provide, which are also separated from each other by 120°. The downhole end 436 of the J barrel further comprises a number of indexing slots 440. As shown, each indexing slot 440 is provided generally between each of the first and second slots. As a result, in the aspect shown in FIG. 42, six indexing slots 440 are provided.

As noted in FIG. 42, the first and second slots, 432 and 438, are separated by first walls 442 having terminal ends 444 that extend in the direction of a respective indexing slot 440. Similarly, the indexing slots 440 are separated by second walls 446, each having terminal ends 448 that extend in the direction a respective first or second slot. As illustrated in FIG. 42, this arrangement of slots 432, 438, and 440, and respective walls, forms a continuous travel path over the circumference of the J barrel proximal to the downhole end 436 thereof. This travel path is adapted to receive the lugs 430 of the lug ring. As also illustrated in FIG. 42, the terminal ends 444 and 448 of the walls are each provided with an angularly arranged end for guiding the lugs through the travel path. More specifically, as a given lug exits one of the first or second slots, 432 or 438, it encounters the terminal end 448 of a wall extending between the indexing slots 440. The angled terminal end 448 serves to circumferentially direct the lug in a predetermined direction, thereby forcing the lug 430 into a given indexing slot 440. As the lug 430 is withdrawn from the indexing slot 440 it encounters the similarly angled terminal end 444 of the first wall 442, which diverts the lug in the same circumferential direction and into the next first or second slot. Subsequently, when the lug is moved from that position it is sequentially diverted circumferentially into the neighbouring slots.

As mentioned above, the lug ring 428 is secured to the housing 424 and is immovable therewith. On the other hand, the mandrel and J barrel and provided in the indexing tool in an axially rotatable arrangement. Thus, as will be understood as the mandrel is axially moved with respect to the housing the arrangement of the slots and lugs mentioned above results in rotation of the mandrel with respect to the housing. Thus, when starting from the lugs in a given first slot 432, as the mandrel is moved in the downhole direction, the lugs encounter the terminal ends 448 of the second walls 446 and are forced to enter adjacent indexing slots 440 caused by the rotation of the mandrel. Further axial movement of the mandrel towards the downhole direction is prevented once the lugs are lodged in the indexing slots 440. At this point, the mandrel 420 is moved in the uphole direction, which forces rotation of the mandrel as the lugs encounter the ends 444 of the first walls 442 and causes the lugs to enter the shorter second slots 438. Again, axial movement of the mandrel 420 is blocked as the lugs enter the ends of the second slots 438. It will be understood that at this point, the mandrel 420 has undergone a 60° axial rotation. As the mandrel 420 is again moved in the downhole direction, the travel of the lugs 430 through the continuous passage of the J barrel causes the lugs to enter adjacent indexing slots 440. Finally, axial movement of the mandrel 420 in the uphole direction causes rotation of the mandrel 420 and causes the lugs 430 to enter into adjacent first slots 432. It will therefore be understood that movement of the lugs from one first slot to an adjacent first slot, as described above, results in a 120° axial rotation of the mandrel.

Referring back to the earlier description, it was noted that the mandrel 420 is secured to the shifting tool 100 in such a manner that relative axial rotation between the mandrel 420 and the shifting tool 100 was prevented. In addition, the shifting tool 100 was indicated as being connected to the remaining uphole portion of the work string by means of a swivel body 400, thereby allowing the shifting tool 100 to axially rotate with respect to the work string. As can therefore be understood as the mandrel 420 is reciprocally moved in an axial direction with respect to the housing 404 of the indexing tool 402, the resulting axial rotation of the mandrel 420 is imparted to the shifting tool. Thus, when a situation is encountered where the shifting tool is unable to sufficiently engage a sliding sleeve, the operation need only manipulate the work string in the axial direction (by extending and withdrawing the works string) with respect to the housing of the indexing tool to result in rotation of the shifting tool 100. By rotating the shifting tool circumferentially by up to 120°, the operator is able to engage a new section of the sliding sleeve and seek to avoid the problem region of the tubing string.

As will be understood, the packer 416, slips 414, and drag blocks 410 and 412, aid in securing the housing 404 in position both axially and rotationally, thereby further ensuring that the reciprocal movement of the mandrel 420 imparts rotation only to the mandrel and shifting tool 100.

It should be noted that the indexing tool described herein offers a unique advantage when operating the aforementioned tools with a work string comprising coiled tubing, since such tubing is not rotatable when in use. In the result, the only manipulation possible with coiled tubing is in the axial direction. Thus, the indexing tool described herein allows axial manipulation of a coiled tubing work string to impart rotational movement to a tool provided thereon. In the above description, the tool being rotated is indicated as being position uphole of the indexing tool. However, it will be understood that such tool may instead be positioned downhole of the indexing tool. In such case, it will be understood that the slots described above would be located on the uphole end of the J barrel. While the indexing tool 402 has been described in relation to axial rotation of the shifting tool 100, it will be appreciated that such tool can be used for manipulating any tool on a work string.

Although the above description includes reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art. Any examples provided herein are included solely for the purpose of illustration and are not intended to be limiting in any way. Any drawings provided herein are solely for the purpose of illustrating various aspects of the description and are not intended to be drawn to scale or to be limiting in any way. The scope of the claims appended hereto should not be limited by the preferred embodiments set forth in the above description but should be given the broadest interpretation consistent with the present specification as a whole. The disclosures of all prior art recited herein are incorporated herein by reference in their entirety. 

We claim:
 1. A sliding sleeve valve for a tubing string, the valve comprising a generally tubular structure having a longitudinal axis and a first connecting end and a second connecting end, the first and second connecting ends being connectable to tubing string components, the valve comprising: a first sub, having a first end comprising the first connecting end and a second end; a second sub, having a first end comprising the second connecting end and a second end; a generally cylindrical housing extending between the first and second subs and having first and second ends, and a wall having an interior surface; and, a generally cylindrical sliding sleeve coaxially located within the housing and having first end facing the first sub second end and a second end facing the second sub second end; wherein: the housing first end is connected to the first sub second end, and the housing second end is connected to the second sub second end; the housing wall includes at least one port for providing fluid communication through the wall; and, the interior surface of the wall has a profile defining at least first and second circumferential grooves provided at spaced separate locations along the longitudinal axis; the sliding sleeve is slidable, with respect to the housing, along the longitudinal axis of the valve; sliding of the sliding sleeve within the housing is limited by the first sub second end and the second sub second end; the sleeve is slidable between a closed port position, where the sleeve covers the at least one port, and an open port position, where the sleeve does not cover the at least one port; the sleeve has an inner surface with a region with reduced internal diameter, wherein the length of the region of reduced internal diameter is less than the length of the sleeve and wherein the region of reduced internal diameter defines a cross-sectional profile, the profile having opposed shoulders; and, the sleeve includes a locating means adapted to engage the first groove or second groove, wherein the locating means is engaged within the first groove when the sleeve is in the closed port position and wherein the locating means is engaged within the second groove when the sleeve is in the open port position.
 2. The sliding sleeve valve of claim 1, wherein first and second grooves are wider than the locating means.
 3. The sliding sleeve valve of claim 1, wherein the locating means comprises at least one snap ring provided on the outer circumference of the sliding sleeve.
 4. The sliding sleeve valve of claim 3, wherein the snap ring is provided within a groove provided on the outer surface of the sliding sleeve.
 5. A shifting tool for shifting a sleeve of a sliding sleeve valve, the shifting tool comprising a generally cylindrical body having a lumen and a longitudinal axis, the shifting tool comprising: two or more sleeve engagement arms provided on the cylindrical body, wherein: the sleeve engagement arms comprise elongate elements having longitudinal axes generally parallel to the longitudinal axis of the cylindrical body; each of the sleeve engagement arms having opposed ends pivotably connected to the cylindrical body, whereby the arms are radially extendable away from the cylindrical body and reciprocate between a retracted position and an extended position; each of sleeve engagement arms having a pair of spaced apart sleeve engagement fingers provided on opposite ends thereof, each pair of sleeve engagement fingers defining a sliding sleeve engagement space there-between; an elongate mandrel having a longitudinal axis and extending generally coaxially through the cylindrical body, wherein: the mandrel is rotatable about its axis within the cylindrical body; the mandrel includes a first portion connected to a rotation means; and the mandrel is provided with pivot linkages for pivotably connecting with each of the sleeve engagement arms; a force transferring means, for transferring rotational motion of the mandrel to extend the at least two arms between the retracted and extended positions.
 6. The shifting tool of claim 5, wherein the rotation means comprises: at least one spiral or helical groove provided on the exterior of the mandrel; and, at least one guide pin provided on a first reciprocating piston provided within the body; wherein, axial movement of the first piston imparts rotational motion to the mandrel as the at least one guide pin traverses the at least one spiral or helical groove. 